This invention relates to a fuel injector for use in supplying fuel under pressure to a combustion space of a compression ignition internal combustion engine. In particular, the invention relates to a fuel injector of the type in which the commencement of injection is controlled using an electromagnetic actuator. The invention is particularly suitable for use in a pump/injector arrangement, but it will be appreciated that the invention may be used in other applications.
In a known pump/injector arrangement, the commencement of injection is controlled by controlling the fuel pressure within a control chamber, the fuel pressure within the control chamber applying a force to a valve needle urging the needle towards its seating. The fuel pressure within the control chamber is controlled using an appropriate electromagnetically actuated valve. Such an arrangement is relatively complex and difficult to control accurately.